Combine marinade ingredients in a bowl and add the cubed chicken. Toss to combine and marinate for 30 minutes or more.
Select Saute on High on the Instant Pot, wait for it to read HOT.
Add about 1 inch of oil and wait for it to start shimmering. Once hot, fry the chicken in one layer if needed in batches until browned and crispy. Remove and set aside on a plate.
Discard oil from the inner pot, leaving only about 2 tablespoons. Add the Szechuan peppercorns and dried red chilies. Fry for about 1 minute, just until fragrant.
Add the rest of the fresh red chilies, ginger, garlic, and bell peppers. Stir and fry for about 2 minutes.
Add chopped green onions and nuts. Fry for a minute.
Add back the fried chicken pieces, stir and add the sugar, rice wine, soy sauce, and sesame oil. Toss to coat. Add the chicken broth.
Close the lid, point the valve to seal. Pressure Cook for 5 minutes, followed by 5 minutes of Natural Pressure Release.
Open the lid, select saute. In a small cup mix cornstarch and water until dissolved and add the mixture to the pot. Stir to combine until thickened.
Serve as is or over rice, garnished with chopped scallions, sesame seeds, and more red chilis.
